/*
 * Copyright (C) 2011 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.zxing.client.android.encode;

import java.util.Collection;
import java.util.HashSet;
import java.util.List;

/**
 * Implementations encode according to some scheme for encoding contact
 * information, like VCard or MECARD.
 *
 * @author Sean Owen
 */
abstract class ContactEncoder {

	/**
	 * @return first, the best effort encoding of all data in the appropriate
	 *         format; second, a display-appropriate version of the contact
	 *         information
	 */
	abstract String[] encode(List<String> names, String organization, List<String> addresses, List<String> phones,
			List<String> phoneTypes, List<String> emails, List<String> urls, String note);

	/**
	 * @return null if s is null or empty, or result of s.trim() otherwise
	 */
	static String trim(String s) {
		if (s == null) {
			return null;
		}
		String result = s.trim();
		return result.isEmpty() ? null : result;
	}

	static void append(StringBuilder newContents, StringBuilder newDisplayContents, String prefix, String value,
			Formatter fieldFormatter, char terminator) {
		String trimmed = trim(value);
		if (trimmed != null) {
			newContents.append(prefix).append(fieldFormatter.format(trimmed, 0)).append(terminator);
			newDisplayContents.append(trimmed).append('\n');
		}
	}

	static void appendUpToUnique(StringBuilder newContents, StringBuilder newDisplayContents, String prefix,
			List<String> values, int max, Formatter displayFormatter, Formatter fieldFormatter, char terminator) {
		if (values == null) {
			return;
		}
		int count = 0;
		Collection<String> uniques = new HashSet<>(2);
		for (int i = 0; i < values.size(); i++) {
			String value = values.get(i);
			String trimmed = trim(value);
			if (trimmed != null && !trimmed.isEmpty() && !uniques.contains(trimmed)) {
				newContents.append(prefix).append(fieldFormatter.format(trimmed, i)).append(terminator);
				CharSequence display = displayFormatter == null ? trimmed : displayFormatter.format(trimmed, i);
				newDisplayContents.append(display).append('\n');
				if (++count == max) {
					break;
				}
				uniques.add(trimmed);
			}
		}
	}

}
